Method of insulating cores



June 21, 1927.

G. L. ROCK METHOD OF. INSULATING CORES Filed se i. so, '1926 ml e/rfar Patented June 21,1927.

UNITED STATES PATENT OFFICE.

.GEOBGE LYHDEN ROCK, OI CICERO, ILLINOIS, ASSIGNOR TO WESTERN ELECTRIC COMPANY, INCORPORATED, 01' NEW YORK, N. Y., A CORPORATION OF NEW YORK.

METHOD OF INSULATING CORES.

Application filed September 30, 1926. Serial No. 138,720.

This invention relates to a method of insulating cores, and more particularly to a method of insulating cores of electromagnetic coils. V

In the manufacture of electromagnetic coils, such as relays and the like, it is the spool heads, thereby insuring that the wire does not come in contact with the metal core.

This construction, however, renders it difiicult, in some instances, to apply the wire upon the core-in smooth formation as is desirable in many types of coils.

The primary ob]ect of the present invention is to rovide a simple and eificient method of insulating the cores of electromagnetic coils in such manner that the wire may be readily applied thereto in smooth formation.

In order to attain this object in accord- 'ance with the general features of the invention, one or more layers of paper or other suitable insulating material is wrapped around the metal core throughout substantially the entire length thereof. Fibre spool heads having apertures closely fitting around the metal core are then pressed over the ends.

of the core into position, thereby spreading the ends of the applied insulating paper outwardly against the inner faces of the spool heads.

In accordance with another embodiment of the invention, the spool headsmay be partially assembled with the metal core before applying the insulating paper thereto. After one or more layers of insulating paper has been applied on the core, the spool 1 eads are then moved toward each other, spreading the end portions of the insulating paper outwardly to bridge the junctions between the core and the spool heads.

Other features and advantages of the invention will become apparent In the following detail description, reference being had to B the accompanying drawing, wherein Fig. 1 is a detail view of the metal core employed in the manufacture of electromagnetic coils;

Fig. 2 is a plan P p Fig. 3 is a detail view of the core with the 1nsulating paper applied thereto;

Fig. 4 is a detail view of the insulated core with the apertured spool heads partially assembled therewith, and

Fig. 5 is an elevational view, partly in section, of a partially completed electromagnetic coil with its core insulated in accordance with the present invention.

In practicing the improved method in accordance with one embodiment of the invention, a metal core 10 is wrapped with one or more layers of insulating paper 11 substantially throughout the entire length thereof, as shown in Fig. 3. The insulating paper is preferably waxed so that it readily becomes attached to the core. Fibre spool heads 12 and 13 having apertures closely fitting around the metal core are then forced over the ends of the core into position, the ends of the core being provided with knurled portions 14 and 15 whereby the a spool heads are securely attached thereto.

view of the insulating 60 The width of the insuiating paper applied to the core is somewhat in excess of the distance between the spool heads of the completed coil. It is obvious, therefore, that the spool heads in being forced into position spread the end portions of the insulating paper outwardly so as to bridge the junctions between the core and the spool heads as indicated at 16 (Fig. 5).

In accordance with another embodiment of the invention, the spool heads 12and 13 are first partially assembled upon the ends of the core 10, after which a sheet of insulating paper is applied to the intermediate portion of the core as shown in Fig. 4. The spool heads are then moved toward each other into position, thereby upsetting the end portions of the insulating paper. as shown in Fig. 5.

It is apparent that the improved method of insulating cores is very simple and inexpensive and provides a smooth joint between the core and each of the spool heads whereby the wire may readily be applied in smooth formation, as shown in Fig. 5. Furthermore, the present method provides an uninterrupted insulation for the metal core which insures the protection of the first layer of wire against contact therewith.

What is claimed is:

1. A method of insulating cores of electromagnetic coils, consisting in applying insulating material to the core, and then as sembling a spool head upon the core in such manner that a portion of the insulating material is spread outwardly to bridge fhe Junction between the core and the spool iea 2. A method of insulating cores of electromagnetic coils, consisting in applying insulating material adjacent an end portion of the core, and then assembling a spool head upon said end portion in such manner that a portion of the insulating material is upset to bridge the junction between the core and the spool head.

3. A method of insulating cores of electromagnetic coils, consisting in wrapping a layer of insulating material around the core, and then assembilng a spool head upon each end of the core in such manner that the end portions of the insulating material are spread outwardly against the inner faces of the spool heads.

4. A method of insulating cores of electromagnetic coils, consisting in wrapping a layer of insulating material around the core, assembling a spool head upon each end of the core, and then causing a relative movement between the core and the spool heads so as to cause the inner faces of the spool heads to abut the end portions of the insulating material.

5. A method of insulating cores of electromagnetic coils, consisting in wrapping a layer of insulating material around the core throughout substantially the entire length thereof, positioning an apertured spool head at each end of the core, and then moving the spool heads toward each other so as to upset the end portions of the insulating material.

6. A method of insulating cores of electromagnetic coils, consisting in wrapping a plurality of layers of insulating paper around the core throughout substantially the entire length thereof, positioning an apertured spool head at each end of the core, and then moving the spool heads toward each other a distance suflicient to upset the end portions of the insulating material so as to bridge the junctions between the core and the spool heads.

In witness whereof, I hereunto subscribe my name this 18th day of September A. D.

GEORGE LYNDEN ROCK. 

